Seed oleic acid phenotype and FAD2-1 genotype association analysis for population 3. Average oleic acid content of soybean seeds produced in Costa Rica from the segregating F6 and F7 RIL developed from the cross M23 × PI 567189 A population 3. X-axis labels indicate a typical commodity soybean line (Jake), the two RIL parents, and the RILs grouped by FAD2-1A and FAD2-1B genotype. AA = wild-type FAD2-1A alleles, aa = mutant FAD2-1AΔ alleles derived from M23, BB = wild-type FAD2-1B alleles, bb = mutant I143T FAD2-1B alleles derived from PI 567189 A; brackets surround the number of soybean seed samples represented in the genotype class. Error bars indicate plus and minus one standard deviation from the mean. Oleic acid phenotype data of each genotype class is the mean of oleic acid content as a percentage of the total fatty acid content of the oil of all lines carrying the FAD2-1 genotype, five individual samples for each line, with the exception of the aaBB class, for which there was only one line and ten individual seeds were analyzed.